cfq: fix build breakage & warnings

* CFQ_WEIGHT_* defined inside CONFIG_BLK_CGROUP causes cfq-iosched.c
  compile failure when the config is disabled.  Move it outside the
  ifdef block.

* Dummy cfqg_stats_*() definitions were lacking inline modifiers
  causing unused functions warning if !CONFIG_CFQ_GROUP_IOSCHED.  Add
  them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-cgroup.h

@@ -27,13 +27,13 @@ enum blkio_policy_id {
 /* Max limits for throttle policy */
 #define THROTL_IOPS_MAX		UINT_MAX
 
-#ifdef CONFIG_BLK_CGROUP
-
 /* CFQ specific, out here for blkcg->cfq_weight */
 #define CFQ_WEIGHT_MIN		10
 #define CFQ_WEIGHT_MAX		1000
 #define CFQ_WEIGHT_DEFAULT	500
 
+#ifdef CONFIG_BLK_CGROUP
+
 enum blkg_rwstat_type {
 	BLKG_RWSTAT_READ,
 	BLKG_RWSTAT_WRITE,

block/cfq-iosched.c

@@ -17,7 +17,7 @@
 #include "blk.h"
 #include "blk-cgroup.h"
 
-static struct blkio_policy_type blkio_policy_cfq;
+static struct blkio_policy_type blkio_policy_cfq __maybe_unused;
 
 /*
  * tunables
@@ -541,14 +541,13 @@ static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg)
 
 #else	/* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
 
-static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg,
-						 struct cfq_group *curr_cfqg) { }
-static void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { }
-static void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { }
-static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { }
-static void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { }
-static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { }
-static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { }
+static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { }
+static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { }
 
 #endif	/* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */